Refrigerating system



Jan. 24, 1939. F. E. coBB REFRIGERATING SYSTEM Filed Jan. '7, 1935 mu 4 Q Z. n fix 7% Patented Jan. 24, 1939;

nnrnlonna'rme SYSTEM mnka. Cobb, St. Louis, Mo., assignor to Louis W. Krueger, Jr., trustee, St. Louis, Mo.

' Application .Ianuary 7, 1935, Serial No. 670

14 Claim.

This invention pertainsto refrigerating systems of the expansion or flooded type and more particularly to systems automatically operated to maintain a more or less uniform refrigerai tion.

In certain types of such automatic systems 'a single condensing unit is arranged to supply a refrigerant to a plurality of refrigerating devices. Such refrigerant is usually supplied in liquid 10, form and the refrigerating device operates to vaporize the liquid, therefrigerating effect being obtained by absorption of heat during such vaporization. The function of the conden'sing unit isto re-absorb the heat from the vaporous re- 15 frigerant and to condense the same to liquid form V for re-circulation in the system. In such installations if the duty required of one of the refrigerating devices is heavier than that of another, there is a tendency-for the condensing unit to operate frequently in response to demands from the heavily loaded device, and as a consequence the other device may have imposed upon it a more intense refrigerating action than is desired.

One of the objects of this invention, therefore, is to provide means whereby the excess service required by a heavily loaded refrigerating device may be supplied without operating the main condensing unit with excessive frequency.

Under certain conditions, as for instance in bars where a special refrigerating device is applied for cooling beer as it is dispensed, an intense and frequent refrigerating action is re- V quired at the beer cooling device and such device 36 must be maintained in service in order to avoid spoilage of the beer dispensed. Accordingly, if for instance the main condensing unit should get out of order so that some time might elapse before itcould be serviced and repaired the beer dispensing refrigerating device would cease to function and its business would be practically suspended until the condensing unit could be repaired.

Another object of this invention, therefore, is to provide extra refrigerating capacity capable of supplying a so-calledhold-over. of refrigeration for a considerable period in case the main condensing unit is-rendered inoperative.

Another object is to provide a heat absorbing on device of novel construction and mode of opera tion capable of providing the extra refrigerating effect required by 'a heavily loaded device.

Another object is to provide'such an absorbing device so arranged that during its operation any oil which may be carried thereto by the flow of refrigerant from the main condensing unitwill not be permitted to accumulate therein but will be transmitted back to the condensing unit.

Another object is to provide such an auxiliary absorbing device adapted to smooth out fluctua- 5 tions in demand upon the main condensing unit imposed by difierent refrigerating devices operating .under different conditions.

Another object is to provide such a'device which may itself be cooled or refrigerated by the 10 main condensing unit. l

Further objects will appear from the following description taken in connection with the accompanying drawing in which the figure representsa view partly in diagrammatical form and 15 partly in section of a system of refrigeration embodying this invention.

The system selected for illustration in the drawing is one including an instantaneous liquid cooler such as is ordinarily used for cooling beer as it is dispensed together with. one or 'more' other refrigerating devices which may beused for gen- I eral cooling purposes, such as refrigerating food I supplies or cooling beer in storage or the like.

It is understood, however, that the invention may 25 be applied to other types of installations to which its action may be suitable.

Referring now to the drawing the main condensing unit illustrated is represented as a com-' pression-condenser of the ordinary type including a compressor I driven by a motor 2 of any suitable type. In the illustration an electric motor is shown. The drive may, however, be by internal combustion engine or other suitable prime mover. The compressor i compresses the vapor- 3 ous refrigerant and delivers the same to a condensing coil shown conventionally at 3 which may be cooled in any suitable manner not indicated in the drawing and in which the vapor is condensed to a liquid and delivered to a receiver 40 4. This unit may be of any ordinary type .well linown in the art. 1

From the condensing unit in accordance with the usual practice a liquid line 5 goes out to the system to r be refrigerated from the receiver 4, 45 while a suction line 6 carries the vapor back from the system to the compressor I. 4 The liquid line 5 may have various branches going to different refrigerating devices. In the illustration .a branch 1 goes to a refrigerating device 8 through an expansion valve or metering device 9 and the vapor is returned by the branch I. to the suction line. The device 8 may be arranged for cooling any desired compartment for storage of perishablematerialandthelike, Thisunitmay i be one of several connected to, and operated by. the main condensing unit.

The operation of the condensing unit ispreferably controlled by automatic means control-- ling the operation of the motor 2. Such means are indicatedat l2. Ordinarily such a device may be connected by a line l3 to the suction line 5 and is usually constructed so as'to .be operable by the pressure within the suction line to close a switch I4 when the pressure reaches a predetermined value indicating a certain rise of temperature for the system. The device l2, though operated by pressure, is in reality a thermostatic device as its functidn is to maintain a low temperature in the system refrigerated by starting the action of the condenser whenever that temperature rises above that predetermined point. Accordingly, although actuated by pressure, such pressure is a function of the temperature and the device [2 may properly be considered a thermostatic device and it will be so named hereinafter, the term thermostatic de-.

vice being used to include either temperature or pressure operated devices.

A so-called instantaneous liquid cooler is represented at II. This may be applied to the cooling of beer, as suggested above, or to other similar service. A characteristic of such a device is that it must operate at frequent intervals and must be capable of quick absorption of a considerable amount of heat. Under such circumstances it may demand considerably more of the refrigerating eflect provided by the'condensing unitthan other devices such as 8. The device ll may be connected to the liquid line 5 by a branch l5 and the vapor may be returned therefrom through a regulating valve IE to a line H. If the return line I! were connected directly to the suction line 6 the extra service required by the device ll might cause the condensing unit to operate at such frequency that the .unit 8 which is also connected-to the suction line 9 would be chilled to too great an extent. In order to balance this effect an auxiliary heat absorbing device is provided.

Such a heat absorbing device may comprise a brine tank l8 in a suitable insulating enclosure l9. The term brine tank as hereinafter used will be understood to include a tankfor any type of freezing solution whether actually a brine solution or of any other type. In fact a solution of alcohol in water is usually used in such a tank and has been found to give satisfactory service. Mounted within the tank I8 is an expansion coil 20 connected to the liquid line 5 by a branch 2| through an expansion valve or metering device 22 in the usual manner. The othenend ofthe coil 20 is connected by a branch 23 to the suction line 6 through a check valve 24 whose function will be described presentlyf In connecting the auxiliary absorbing device to the system the coil 20 is connected as already described while the coil 25 has its inlet connected to the line H and its outlet connected by a branch 29 to a cross line 39 to which the branch 23 of the expansion coil is also connected.

The line 30' extends from the outlet line I! of the instantaneous cooler II to the suction line 9 and has connected thereto, as described, the branches 29 and 23. Included in the line and so as to separate these branches from each other and from the line I! are check valves 9| and 32. These valves are set to open in response to a flow of vapor therethrough from the line H toward the suction line 6, but to close so as to prevent a flow-in the reverse direction. These valves are preferably. spring-controlledand adjustable so as to open at a definite pressure. The adjustment is usually made sothat the valve 32 is set at a slightly higher pressure than the valve 25, while the valve 9| is set at a slightly higher pressure than the valve 32.

The operation of this system is as follows:

Assuming that the system is started up for the first time with all parts at atmospheric temperature,=the motor 2 is started by closing the line switch 33, the switch l4 being closed automatically on account of the temperature. This sets the condensing unit into operation so that the vaporous refrigerant in the system is compressed temperature to the desired point. This is usually around 22 F. and the solution maybe such that a certain amount of ice is formed in the brine tank l8. When the proper temperature has been established in the system the pressure in the suction line 6 is reduced sufllciently so that the device l2 operates to open the switch It and shut down the condensing unit.

The action of the device 8 may follow the ordinary routine usual to such devices. This is included in the illustration to represent one or more standard devices of this type which may be included in the installation.

The device II will ordinarily operate at frequent intervals and will absorb a considerable amount of heat so that a considerable volume of vapor'is developed thereby and delivered to the line II. This vapor passes into the condensing coil 25 and is condensed to liquid therein. If the production of vapor by the device I I should occur in sufliciently large volume the pressure in the line I! would increase to a suflicient extent to open the check valve 3|" and permit the excess vapor to pass down the branch 29 and into the outlet end 21 of the coil 25. Accordingly, both ends of the coil 25 may be utilized for condensing the vapors produced byv the device H. Under ordinary operation the inlet end alone will accommodate the vapors produced. The arrangement of the valve 3 I, however, is such as to render both ends of the coil available in case of need. As the refrigerating capacity of the solution in the tank I8 is considerable, condensation of vapors received from the device I I may continue for a considerable period of time before the temperature of the solution is raised to a great extent. Such temperature, however, does increase gradually and in accordance with such increase the pressure in the outlet line 21, 29 gradually rises. After a great to open the valve 32 whereupon any uncondensed vapor may flow along the line 30 past the valve 24 and into the suction line 5. Here it establishes increased pressure in the starting certain period this pressure becomes sufficiently and 30 open and draws the uncondensed vapor from the line 21, 29. The reduced pressure established in this end of the coil 25 now promotes evaporation of the condensed refrigerant liquid in the lower coils thereof. Such evaporation in turn produces a refrigerating effect absorbing heat from the solution and again reducing its temperature to the desired point. When such temperat re is attained the pressure in the suction line is again reduced to a value such as to cause the automatic device I! to shut down-the condensing unit. In this way the extra refrigerating capacity of the brine tank I8 is made use of to lengthen the cycle of operation of the condensing unit to such a value as to be proper for taking care of the requirements of the device 3 and such other similar devices as maybe connected to the system;

The expansion coil and its expansion valve or metering device 22 are so adjusted that a certain amount of refrigeration is provided thereby in a substantially continuous operation. This effect is adjusted to a low value suflicient to take care of leakage losses of heat in the tank It and such other requirements as may resultfrom irregularities in the operation ofthe system. I

It will be noted that'the coil 25 provides both a condensing coil and expansion coil. The vapors pasdng thereto from the line H are condensed during the period when the main condensing unit is shut down. On the other hand, while the condensing unit is operating the liquid in the coil 25 evapora es and thus produces the cooling effect of an expansion coil. Furthermore-this auxiliary absorbing device has a substantial refrigerating capacity once it has been cooled down to the proper temperature. The tank is usuallyconstructed of such dimensions as to have a'refrig- V crating capacity capable of carrying the load imposed upon it by the device H for a period of say four or five hours. Accordingly, incase of accident to the main condensing unit such as to interfere with its operation. the system will continue in operation for a sumcient length of time to enable the main condensing unit to be serviced and put in proper repair so as to resume opera.-v tion usually before the refrigerating capacity of the brine tank is exhausted.

An important feature of this device is that when lubricating oil used for lubricating the compressor I is carried into the refrigerating system,

as is usually the case in a pressure condensing system, such oil finally finds its way into the coil 25. Here it is carried through the coil from the inlet to the ou let side with the condensing liquid refrigerant. Upon subsequent evaporation of the refrigerant during operation. of the condensing unit such evaporation usually takes place with a considerable amount of ebullition so that the oil contained in or floating upon the liquid refrigerant is' thrown up in the form of a spray and is carried with the vapor out of the coil 25 and back through the suction line to the crankcase of the compressor I. It has been found that during normal operation only a small percentage of the total quantity of oil in the system is found at any time in the coil 25. Accordingly, this device operates to return to the compressor. any lubrieating oil that may flnd its way into the system.

' In order to insure continuous operation and prompt correction of trouble. an indicating device is provided adapted to give a warning of failure of the condenser unit to operate when it should. An automatic device 34 similar to the switch I! is ated by the pressure therein. This device is ad-' justed to operate at a pressure slightly above that for'which the device I2 is adjusted. Accordingly, the device 34 will not operate untila pressure somewhat higher than that ofthe device i2 is active in the-suction line. The device 34 controls a switch 35 which in turn controls a signal device such as a lamp 36 located at'th'e station of the attendant so that his attention will be attracted connected to the suction lineii so as to .be operthereby. This device is preferably supplied by a separate source of power such as a battery 31. It will be clear that this arrangement is adapted to give warning of 'any failure of the main condenser. Supposing. for instance, that the power supply 33 should fail or that there should be trouble in the motor 2 or for any other reason the condensing unit should fail to operate, the

given to rectify the trouble and maintain the systern in operation.

It will-be seen that this invention provides a simple'and effective arrangement for smoothing out the peaks in the operation of such a device as H and to convert the load to which the system is subjected thereby to a relatively steady load. This makes it possible to operate on a condensing unit having a relatively long cycle of operation and the cycle may be adjusted by providing proper capacity in the auxiliary absorb ng device so that other normally operating dev ces such as 8 may function satisfactorily on the same system. The absorbing device furnishes an auxiliary means for condensingthe refr gerant and provides for a definite direction of flow therethrough,

By the expansion coil 20 the system mey be started up at any time from atmospheric temperature and will automatically take up normal operation after a certain lapse of time sufflcient to cool the brine in the tank l8 to the pro er temperature. The device further provides considerable holdcver capacity so that in case of trouble the system may be kept in'operation until the trouble can be corrected. This is assisted by the fact that the indicating device 34, 36' gives prompt warning when attention is required for the correction of any trouble.

While this embodiment of the invention has been described as constituting a unitary sys em, it will be understood that individual features or sub-combinations thereof may be useful by themselves without references to other features, and that the use of such individual features or sub-- is obvious that various changes may be-made, within the scope of the appended claims, in 'the details of construction without departing from the spirit of-this invention; it is to be understood, therefore, that this invention is not limited to the specific details shown and/or described.

Having thus described the invention what is claimed is:

1. In a refrigerating system of the character described having a main condensing unit, and an evaporator connected thereto; an auxiliary refrigerating device, comprising, a brine tank, a condensing coil therein open at one end to said evaporator and at the other to the suction side of said unit, and means independent of said coil for cooling the brine in said tank.

2. In a refrigerating system of the character described having a main condensing unit, and an evaporator connected thereto; an auxiliary refrigerating device, comprising, a brine tank, a

condensing coil therein open at one end to said evaporator and at the other end to the suction side of said unit, and a cooling coil in said tank, said last coil being connected to receive refrigerant from said unit independently of said first coil.

3. In a refrigerating system of the character described, a main condensing unit, a plurality of expansion elements connected to receive refriger-. ant from said unit, and an auxiliary refrigerating device connected to receive refrigerant from said unit and allthe refrigerant vapor from one or more of said elements, connections to deliver uncondensed vapor from said auxiliary device and said elements to said unit,'another of said elements being connected to deliver refrigerant vapor directly to said unit.

' 4. In a refrigerating system of the character described, a main condensing unit, aplurality of expansion elements connected to receive refrigerant from said unit, and an auxiliary refrigerating device connected to receive refrigerant from said unit and all the refrigerant vapor from one or more of said elements, connections to deliver uncondensed vapor from said auxiliary device and said elements to said unit, another of said elements being connected to deliver refrigerant vapor directly to said unit, and means to prevent flow of refrigerant vapor from said other element to said device.

5. In a refrigerating system of the character described, a main condensing unit, a plurality of expansion elements connected to receive refrigerant from said unit, and an auxiliary refrigerating device connected to receive refrigerant vapor from one or more of said elements and to deliver the same to said unit, another of said elements being connected to deliver refrigerant vapor directly to said unit, and an expansion coil for cooling said device connected to receive refrigfrom one or more of said elements and to deliver uncondensed vapor to said unit, another of said erant from said ,unit.

6. In a refrigerating system of the character described, a main condensing unit, a plurality of expansion elements connected to receive refrigerant from said unit, an auxiliary refrigerating device connected to receive refrigerant vapor elements being connected to deliver refrigerant directly to said unit, and means to indicate failure of said unit to operate.

'7. In a refrigerating system of the character described, a main condensing unit, a plurality of expansion elements connected to receive refrigevaporator connected thereto; an auxiliary refrigerating device comprising, a brine tank a condensing coil therein connected to receive refrigerant vapor from said evaporator, said coil being constructed and arranged to condense the gaseous refrigerant and to evaporate the liquid refrigerant condensed therein in accordance with changes of pressure in said coil and temperature in said tank, means for withdrawing the evaporated refrigerant from said coil, and separate means for cooling the brine in said tank.

9. In a refrigerating system of the character described having a main condensing unit and an evaporator connected thereto; an auxiliary refrigerating device comprising, a brine tank, means for cooling the same, a condensing coil therein having an inlet connected to receive refrigerant vapor from said evaporator, said coil being constructed and arranged to retain theliquid condensed therein and having an outlet connected to the suction line of said unit so as to evaporate the condensed liquid when suction is established, and means operable to connect said outlet to re ceive refrigerant vapor from said evaporator in order to condense such vapor in said coil.

evaporators connected in a circuit with said unit,

a particular evaporator connected with said unit in a separate circuit from said first evaporators, and an auxiliary refrigerating device connected insaid separate circuit to receive vapor from said particular evaporator and to be cooled by operation of said unit.

11. In a refrigerating system of the character described, a main condensing unit, one or more evaporators connected in circuit with said unit, a particular evaporator connected with said unit in a separate circuit from said first ,evaporators, and an auxiliary refrigerating device having a condensing coil connected in said separate circuit to receive refrigerant vapor from said particular evaporator in order to condense such vapor in said coil, and a separate evaporating 'coil in said device connected to said unit in order to cool said device. I

12. In a refrigerating system of the character described, a main condensing unit, an evaporator connected thereto, an auxiliary refrigerating device having means connected to receive vaporous refrigerant from said evaporator and to deliver vaporous refrigerant to said condensing unit, and separate cooling means in said device connected to be refrigerated by operation of said unit adapted to cool said first means.

13. In a refrigerating system of the character- ,described having a main condensing unit and an and at the other end to the suction ide of said unit, said cofl being formed to retain refrigerant condensed therein, and separate means connected the system so as to receive refrigerant vapor therefrom in order to condense such vapor in said coil, and means connecting said coil with the suction line of said unit in order to evaporate condensate contained in said coil.

FRANK E. COBB. 

